The present invention relates to a collapsible square that can be folded into a storage position and unfolded to a deployed position capable of measuring predetermined angles.
Squares are frequently used in the construction industry to layout and mark building materials. Squares are used, for example, during framing, tiling, cabinet installation and masonry work. Squares have two or more legs that form an angle such as a 90 degree angle. One leg is placed against a first structure, such as a foundation or floor, and the second leg is used to position or mark a second object, such as a sheetrock panel or a board used to construct a building frame, relative to the first structure. It is desirable that the legs of the square be long enough to span a substantial length along each structure to facilitate the positioning or marking. Therefore, the legs of the square are typically several feet long.
Because the legs of the square are long and are perpendicular in use, squares in their deployed positions are large and cumbersome to transport and store. Consequently, many squares are constructed so that the legs are movable relative to one another so that the square can fold or xe2x80x9ccollapsexe2x80x9d into a storage position when not in use. Although the ability to move the legs of the square between deployed and folded positions facilitates transport and storage of the square, the manner of connection between the leg portions sometimes interferes with straight overlapping alignment of the leg members in the storage position or requires disconnection of one or more joints to move the legs into their storage position. Other squares provide for a movably adjustable connection between the leg members. However, the movable connection between the leg members may introduce the requirement of tedious angular adjustment to a desired angle and the possibility of slight angular misalignment when the square is moved into its deployed position.
Many squares include two elongated legs that form an angle and an elongated member or brace that holds the elongated legs in angle forming relation. U.S. Pat. No. 4,955,141, for example, shows an adjustable square that includes two legs that are pivotally mounted together and an elongated blade member that functions to releasably hold the two legs in a selected angular position. The elongated blade member is pivotally connected to one leg and slidably engaged within a longitudinally extending slot in the other leg. This type of device does not automatically move into a right angle position when fully deployed. In addition, they do not form a true right triangle, as the leg members extend beyond the intersection with the hypotenuse.
Many squares have three legs that are mounted together for movement between folded and deployed positions (and/or for angular adjustment) by sliding connections or by a combination of sliding and pivoting connections. U.S. Pat. No. 1,640,604, for example, shows a combination square having three legs, two of which are pivotally connected together and the third of which is slidably engaged with the first and second legs for angular adjustment. Patent reference WO 98/47,720 shows a square in the form of a 3-4-5 right triangle having two legs pivotally mounted to the largest leg (the hypotenuse) and slidably engaged with each other for movement between storage and deployed positions. One disadvantage of WO 98/47,720 is that the compactness of the square when in the storage position is limited by the length of the hypotenuse leg. Another disadvantage of many prior art squares is that they do not enable the square to be automatically and effectively locked in a right angle, deployed configuration.
In addition, sliding linkages between adjacent legs are generally disadvantageous because they are a possible source of inaccuracy when the square is set in a position of angular adjustment or when the square is moved to its deployed position. Thus, although sliding connections allow angular adjustment, these connections introduce the possibility of error and increase setup time. For squares that are movable between a folded position and a single deployed position, however, sliding connections are particularly undesirable because they introduce the possibility of error while providing no compensating advantage of allowing adjustability in the deployed position. Pivotal connections are more advantageous when a square assumes only two positions, a folded storage position and a deployed in position. Consequently, there is a need for square that is movable between storage and deployed positions using only pivotal connections between adjacent legs for movement between storage and deployed positions.
An objective of the present invention is to meet the need identified above. To meet this need, a collapsible square constructed according to the principles of the present invention includes a first elongated rigid leg having first and second ends and a second elongated rigid leg having first and second ends. The second elongated rigid leg is pivotally connected at its first end to the first end of the first elongated rigid leg. The collapsible square further includes a hypotenuse member comprising two elongated rigid leg portions. A first of the leg portions of the hypotenuse member and a second of the leg portions of the hypotenuse member have their first ends pivotally connected to the second end of the first elongated rigid leg and the second end of the second elongated rigid leg, respectively. The first of the leg portions and the second of the leg portions have second ends thereof connected to one another in a manner which permits the hypotenuse member to be folded. The first leg, the second leg, and the hypotenuse member are connected to one another so as to be movable between 1) a storage position wherein the first leg, the second leg, and the hypotenuse member are disposed in linear overlapping relation with one another, and 2) a deployed position wherein the first leg, the second leg, and the hypotenuse member form a right triangle. A releasable lock structure disposed at the second ends of the first and second leg portions is constructed and arranged to releasably lock the first leg, the second leg and the hypotenuse member in the deployed position.
Another object of the present invention is to provide a collapsible square that automatically sets the right angle once the square is moved into the right angle configuration, without the need for manual adjustment or manipulation. Accordingly, the present invention provides a collapsible square that comprises a first elongated rigid leg having first and second ends, a second elongated rigid leg having first and second ends, the second elongated rigid leg being connected at said first end thereof to said first end of said first elongated rigid leg, and a hypotenuse member connected to the second end of the first elongated rigid leg and the second end of the second elongated rigid leg, respectively. The rigid legs and the hypotenuse member are connected to one another in a manner that permits the square to be movable between 1) a storage position wherein the first leg, the second leg, and the hypotenuse member are disposed in linear overlapping relation with one another, and 2) a deployed position wherein the first leg, the second leg, and the hypotenuse member form a right triangle. A releasable lock structure at the second ends of the first and second leg portions automatically locks the elongated rigid legs and the hypotenuse member in the deployed position when the leg portions and the hypotenuse member are moved into the deployed position.
Other objects, features, and advantages of the present invention will become apparent from the following detailed description, the accompanying drawings, and the appended claims.